Traction-wheel.



C. R. TWITCHELL.

TRACTION WHEEL.

APPLICATION FILED APR.11. 1917.

Patented July 2, 1918.

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application tiled. april 1l, im?. "teral lt'o. lehnte.

'of the invention, such as will enable others sllled in the art to which it appertains to make and use the same.

My invention relates to that class of carrying and laying wheels provided with a track over which the wheels roll and which is automatically laid down and taken up as the wheel progresses and has particular reiference to the joint, the connection between the shoes constituting the track, and the rim ot the wheel.

llnthe accompanying drawing, Figure l is a side elevation of a traction wheel embodying my invention.` Fig. 2 is section on the line 22, Fig. 1, and Fig. 3 is a perspective of one ot the shoes.

Referring to the drawing the shoes l are arranged in two series of staggered disposition as well known in the art, that is, the shoe of one series overlaps the adjacent edges ot the shoes of another series. They are mountedl'in the rim of a traction wheel 2 driven by any appropriate mechanism.

With the view to providing an etlicient and removable joint or connection between the shoes l and the wheel-2 ll construct each ot the shoes ont three parts. The part 3 is a metal casting and the parts d are blocks bolted to the casting at each of its sides as at 5. rlihe casting 3 has formed integrally with it a link 6 which passes through a slot 7 in the Harige 8 ot the wheel rim. 'At the inner extremity of this link is a knob '9 loosely held on the link by a pin 10, the knob being preferably rabbeted to receive the end ot the link. he shown in Fi 21, thepknob is wider than the slot 7 in the w eel rim so that when the shoe l2 is in the position of Fig. l it will out. 'llhis enables me to make the slot long enough to ilsure the necessary swing ot the link and s oe.

'llhe knob is shown ot convex formation as lat 13 to provide a rolling surface which ineures the shoe gravitating into the proper position on reaching the ground.

The link 6 has its edges curved so as to cause the link to taper bodily toward the knob 9. This curvature varies with the diameter ot the wheel. its purpose is to provide a formation which will co-act with the convex surface ot the loosely mounted lmob 9 to adapt thelink to the curvature of the wheel and to the angles the shoes assume relatively 'to the wheel, and thereby lessen friction.

lt will be understood that the described link connection applies to all of the shoes, and that the primaryA advantages are the readiness with which shoes may be removed and replaced by withdrawing the pins 10, and the reduction of friction in the swing of the shoes. ,l

l claim as my invention:

l. ln a traction wheel, the combination with a wheel rim having a slot, of a tread shoe having a link passed throu h said slot, and a knob loosel mounted on t e inner end of the link, said link having its edges curved to taper the link toward the knob.

2. ln a traction wheel, the combination with a wheel rim having a slot, ot a tread shoe having a link passed through said slot,

l and a knob of convex formation to provide a rolling surface on the wheel rim and loosely mounted on the inner end of the link, said Y link having its edges curved to taper the link toward the knob.

3. ln a traction wheel, the combination with a wheel rim having a slot, of a tread shoe comprising a pair ot blocks and a castingkbetween and secured to said blocks, a l1n integral with said castin and passed 'through said slot, and a knoblcrumed on the inner end of said link.

4. ln a traction wheel, the combination with a wheel rim having a slot, of a tread shoe comprising a pair of blocks and a casting between and secured to said blocks, a link integral with said casting and passed through said slot, and a knob fulcrumed on the inner end of said link, said mob being wider than said slot and ot convex formation to provide a rolling surface on the wheel rim..

5,'lln a traction wheel, the mmhination with a wheel rim having a slot, ot a tread shoe comprising a pair of blocks angl a cast-A ll'it b "Hwy t@ tra..

ing between and l till lill

ddh

link integral with said casting and passed testimony whereof, I havesigned this through said slot, said link having its edges speclication in thepresence of two subscribcurved to taper the lilik, and a. knob rfuling Witnesses.

orumed` on the'inner end? of Said 1inksad CHARLES R TWITCHELL. 5 knob being wider than said slot and of Witnesses:

convex formation to provide 'a rolling sor- E A Bm? face on the wheel` J... 

